Transmission



J. T. BARRON TRANSMISSION Filed 001:. 29, 1947 Aug. 15, 1950 //v l/ENTOR JOHN TBARRON A TTOR/VEVS Patented Aug. 15, 1950 UNITED STATES PATENTOFFICE f f 3 2,518,51 j. I

v V v TRANSMISSION H John '1.v Barron, South Easton, Mass, assignor toCharlesE; Crofoot Gear Corp South Easton, 1

Mass., a corporation of Massachusetts Application-OctoberJ29, 1947,Serial No. #8 2,918

My present invention relates to transmissions and particularly toreverse gear units. I

' For marine uses a reverse gear unit must b of simple and durableconstruction and combine fease and reliability with an adequate'torquecapacity in reverse and a'definite neutral position. Many reverse gearunits have been proposed, but

eventhose that are-in commercial use fail to:

meet such general requirements. 7

1A transmission to couple axially alined drive and driven elementsina'ccordance with my invention eomprisesra'pair of-bevel gears, one ofwhichis anchoredsto'one of the elements and the other of'which'is keyedto the other of the elements. Each 'g'ear includes ashoulder disposed,in an axial direction, opposite to that of the other gear. 'Anopen-ended housing for the bevel gears is ofsufficient length to overliea substantial part of the shoulders of 'the bevel gears. Mounted in thehousing are pinions' in mesh with the bevel gears and the housing issupported OrrealGh bevel gear shoulder by antifriction elements whichcouple the housing and the unanchored bevel gear against axial movementrelativeto the anchored bevelgear thereby tomaintain proper gearoperation. Wher'e my invention is embodied in a reverse gear unit;reverse drive is established by means of a brake of any desired typewhich holds the housing against rotation and a clutch adapted to couplethe housing and one'of'the elements together provides aforward drive. v

"In accordance with my invention, the clutch "consists of at least oneclutch plate slidably mounted on aspline portion on one of the elementsadjacent the extremity of the shoulder of 1 its bevel gear and at' leastone clutch plate slidably splined to an .extension of the housingwhichoverlies the spline portion and establishes, with the housing, ashoulder constituting a backing element. -Brefer'ably,,that shoulder isdisposed so that the extremity of the bevel gear 2 Claims. (prim-W0)all) .shoulder adjacent the spline portionalso conan--illustrativeembodiment of my invention,

a reverse gear unit fromwhich its novel features and advantages will. bereadily apparent.

In the drawings: a I Fig. 1 i a longitudinal section through the reversegear unit.,

-Fig-. 2, is a section along the lines 2-2 of 1, and i a :Fig. 3 isafragmentary section, on anenlargedscale, showing the rotary seals.

vI have indicated at 5 a drivewshaft having-a 'shoulder 6. A bevel gearI having a shoulder 8 establishing a hub 9 is keyed as at Ill to the endportion-H of thesha'ft 5. The gear I is anchored against axial movementrelative :to the shaft 5 bymeans of. a disc l2 locked to the shaft endH'by abolt l3 toseat the extremity of the hub '9 of the" bevel gearagainst the shaft I4, but is not locked thereto against axial movement.1

I provide .a housing '20 which is preferablyein the form of anopen-ended cylindenthe inside diameter of which-is slightly greaterthanthe diameter of the bevel gears 1 and I6. and is of suificient length tooverlie their'relatively long hubs 9 and |8which are disposed inopposite di rec'tions. The housing 20 supports a plurality of pinions 2|and is in turn supported on 'thebeve'l gear hubs by anti-frictionelements 22 which are preferably ball bearing units. The races of suchunits are maintained against axial'movement by the wedging action'ofthe; retaining rings 23 and 24 positively seatin the races of theelements 22 against'the'shoulders oft the bevel respectively: y By thisconstructiom the housing 20'and the unanchored' bevel gear I6 arecoupledto the anchored bevel "gear 1 againstaxial movement relativethereto thereby to maintain proper gear alinement. V a 3 While thepinions 2l may be mounted in any desired Way, it is desirable to avoidthe necessity of machining theinside diameter of thehousing '20 to closetolerances. For that reason, I

' e'arsand the shoulders 25 of the housing" 2|] provide the housing-'20with a plurality of radial bores'26 into which pinion'supports 21' areadjustably threaded. Each support 21 has a flange 28 to provide a backinfor the bushing 29 for the pinion 2!. By this construction, the housing20 may be inexpensively established and the pinions 2| individuallyadjusted to provide proper gear alinement. Each support 2'! may then belocked in position by any suitable means. To accomplish such locking ofeach support, I have showxrea gpaii 'of set screws SO threaded. into oneend'of the housing 20 in parallel with. its axis of rotation to engagewith the support. As shown in the drawings, the supports 21 areproportioned so that they do not protrude .from the outer surface of thehousing 20 in any operative position.

At 3|, I have indicated ahrakaband'encircling the housing 20. The brakeband 3| issupported at 32 and while it may be positionedxoperatively byother means, I have shown its upturned end 33 supporting the rod 34which carries "a *piston 35 mounted in the cylinder 36 supported on theother upturned end 3-1 of thebi'ake :band 34.. The cylinder-3E has aportto=whicir the pressure supply conduit 38 is connected..- Ehebrake bandends 33=and 31 *are eao h hraeedl 'as:- at 3 9.

Splined to the shaft I4 betweenrtherextremity of the hub fil of thehvehgear' l fi and the'sshaft shoulder I is a gear 40 as aconvenientmeans 'df providing. asplined pettionrtorslidably support aset of clutch pl'ates H, lfformitheahousing. 2'9 wi;:th=an;extension 42overlymgtthesgear ws The extension- 442; has a shoulder=:43"rearwardlyrof which it is" slotted as: at flitorslidablysupportass'et; ot'clutchplates di eachsof which beingspaced fronranother byone-of thezclutch: plates 1 l. The shoulder 43 establishes a backingelement and *is alined with thesextremityef the bevelsgear hub aresothatitherhuh 1m :also-eonstitutesm martrof rtheibackingi-elementt l neslots at also slidabiyrsupportfa.fpressure plate 143*. fhavesshowrr the,pressurefiplate '45 as actuated by fluid under "pressure to "clamp :the'"fillllth plates. togethervagainst thesbacking elemen-t; 'Toaccomplish:this,. 2bolt1to+the endlbf "the housing-entensionli are endplate- 41 having epair of annular extensions rlls anddisposedfiowarflsth pressure mater-teem avpain stannular extensions 50 and 5|disposed imtheropposite direction The pressure ;.plate :4 G-ihasta' pair'of'l-sannnlarflanges fieawh-iciradefine with the extensions-48andvlflia chamber Etandmh-ich fcarry suit ablerannnl-arssealsziii to:seal; the: cham- :ber 54 rthroughoutfithe'nzelativelyshort stroke :oftherpressureeplatedfil. The acndzrplate 44 1 rat 'leastsoneportifilocated between the extensions 150 andiil.

nt 5'r,. I have simwn arholderrsurroundingthe "driven shaft 2 4- randheld against mutation by a support indicated at: 58. 'Theiholderthasanannularextension 159 idisposedrtowardsithe .plate :41 and is rprovidedwithiaxradiahpassagefill to which BTQI'BSSIII'G? supply;conduitsindieated at G lis connected; The extens-ion 'iafhas a port 6-2.inzcommunication with the passage 60 located-between direextensions-xfiflzand iil oflthe; plate 41.

.Rotarwseals generally indicated iat .63: andifid, are seated-"on theirmeriand outer surfaces,v respectively, r ofs: the annular :extension'59 1 and are in engagement with the annular extensions ':5l and :50,respectively, 170 establish a .pressure chamber 65.

.The "seal :64:- (see :Fig. '3)- includes an: annular contactzfifiyieldahly maintainediagainst the anrmlar extension 50by-means-ofsprings-2 Blrseated the sealr'carriertfis withreference: towhich .the

.:contact 86 zisaslidable-vand whichi'isrzsubstantially U-shaped incross section. A ring 69 is a press fit on the inner part of the carrier68 and defines with the contact 66 an oil passage 10 which efiectscommunication between the chamber 65 and the rear end of the contact 66so that fluid pressure in the chamber 65 is available to urge thecontact 66 against the extension 50. For that reasom -zasseal lhpreferably rof ithemerin ype, is disposed hetweenthe contact 63 and'iitscarrier 68. The carrier 68 and the ring 69 are keyed together as at 12.

The rotary seal 63, while it may be of the same construction as the seal64, is shown as comprisinga-contactn carried on an annularsupportfltbetweenwhich and the annular ring 15 entire-extension 59 is aseal 16. The support 14 :zhas:a.-shoulder. .=I.'l-between which and theseal '16 is a spring 18 urging the contact 13 against 'the extension 5|and which is positioned relative to the extension 59 to enable fluidpressure to enter 'finsibaclc ofthershoulder llsolthat fluid pressure isavailable :toassistdn "maintaining the rotary sealzSi-Ia-operativewith:respecttosthe-extension 5 l Itwwill :be :understood. that thetransmission showrrito illustrate my inventionisf itself. housed.tomrnvide ran oil "reservoirsuch as 'I have findipatent:at:Ir9rholdinga. much greater volume. of on than could; :hercontained. in.the housing 20.

To ensure the circulationrofpiliimthe reservoir .19 throughtiter-transmission and zparticularly through. :the 'smeshed bevel :and'.pinion gears, :I .previderthevhousingj ll zwith: a-rplurality .of holes:Eflzpreferahiy located rb'etweentthe :shoulders .25.Hecausezotthe-:gear:train which :1: use, a.;definite oil cinculatinn. isestablished :whemthe transmis- TSiOIElSZ imreverseidriue andatheyhousing20 isheld ngainstirotation. :The'positive circulation; of. .oil.:thronghz:thaethoushigi2ilzisa alsoirnportant in thatz'preuentsthe-'zaccumulation-ioirsludge .Ltherein.

Eromzithetioregoing, itwill. be:zapparent that:therneversegearmnits;ineaccordance with my'inmention aressimple. -.and@compactin. construction :and are-- adapted tmgive longaand; efficient:service hecauseathe housing Zmandithe bevcl gear :ifi-are positively.located withireferenceato the. anchored bevel gear .1.

Whileneither the :brake :nor 1 the clutch 1 need zine-operatedby" fluidpressure,such-operation is preferred. lIniaddition to smooth and properbrake .and clutch operation which ,fluid ;=pressurezensusessitteliminates: mechanical brake and clutch operating mechanismswhich-areobjec- -.tionable-in construction because-.ofexpense and the-*necessityof ;.providing for their adjustment and in. operation because of'.zdrag. .-Such. gdrag nausea-partial shaftrrotation. when .the controlmeans :are neutrally positioned: with resulting heating whichcausesnwear.

' What -therefore claim and desire to secure by LettersPatent is z I. Areverse gear; unittorconnect first and second shafts, said unitcomprisingfirst and 'secend bevel gears, each-.one-of which includes asi iould'ered-hub having aspli'newayito enable-it to -beconnected. to.one of the shafts, means :at- 'tae'hable to said first shaft to lock thegear splined: thereto against axial- :movement', a .uni-

tary open-ended :cylin'd'rical :housing enclosing said -bevelrgears' apiniomrotatably supported by saidehousing and in mesh: with. said: bevelgears, said housing being of'sufiicientlength to overlie'a substantialpart'o-f iboth. hubs rand "having each of its ends counter-bored toprovide a shoulder radially alined with the. shoulder :of one :of thebevel gear jhubs, .aibearirrg innit-interposed be,-

tween each hub and the counterbored housing ends, and means anchoringsaid bearing units against said radially alined shoulders thereby toposition said second bevel gear against axial movement relative to saidfirst shaft.

2. A reverse gear unit adapted to connect a driving shaft to a drivenshaft comprising a unitary, hollow, open-ended, cylindrical housinghaving substantially the same diameter throughout its length, a piniongear rotatably mounted in said housing intermediate its ends, a drivinggear having a hub adapted to be coupled to said driving shaft located inone end of said housing and meshed with said pinion, a driven gear havina'hub adapted to be coupled to said driven shaft. located in the otherend of said housing and meshed with said pinion, means to lock one ofsaid gears to its shaft to prevent axial movement therebetween, means torotatably mount said driving and driven gears in said housingand tomaintain them in mesh with said pinion comprising a counterbore in eachend of said hous- REFERENCES CITED,

The following references are of record in the file of this patent:

Ur rr'nb STATES PATENTS Number A, Name Date 707,396 Darling et a1. Aug.19, 1902 954,169 7 Clarke Apr. 5, 1910 1,663,838 Harmon Mar. 27, 19282,009,191 Buckles July 23, 1935 2,018,0'14 Fahrney Oct. 22, 19352,189,109 Hacker Feb. 6, 1940

